Monday, April 3, 2017
This calyx was found while sifting through matrix while looking for dis-articulated crinoid arms for another fossil. It is quite a find measuring a little over 3 cm in width and it has part of gastropod fossil (see arrow) located near the top of its folded up arms.
This crinoid appears to be a Pterocrinus acutus. The creature existed in the Mississippian Period and was found in the Glen Dean member of Grayson County Kentucky USA. This next image has 3 arrows highlighting the spines on the arms.
Side view of spines below.
Thanks to Kenny for the images.